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1.
Carotid baroreflex function ceases during vasovagal syncope   总被引:2,自引:0,他引:2  
Abstract. Despite the arterial baroreflex control of heart rate and blood pressure, vasovagal syncope is a common cause of loss of consciousness in people exposed to stimuli that reduce the central blood volume, such as head-up tilt. Carotid baroreflex function was evaluated using a rapid pulse train of neck pressure and neck suction in three conscious volunteers who developed a vasovagal episode during head-up tilt. The maximal gain of the carotid-heart rate and carotid-blood pressure baroreflex function curves were identified as measures of carotid baroreceptor responsiveness. When presyncopal symptoms developed, one further baroreflex assessment was obtained before the subjects were returned to the supine position. The bradycardia and hypotension exhibited during pre-syncope and syncope reflected a leftward and downward relocation of both the cardiac and vasomotor stimulusresponse curves. In addition, during the vasovagal syncope, baroreflex control was suppressed as blood pressure remained low during neck pressure stimuli. In conclusion, arterial baroreflex function ceases during vasovagal syncope.  相似文献   
2.
Treatment of mouse L929 cells with immune T (type II) interferon resulted in the induction of two double-stranded (ds) RNA-dependent enzymes which have been described previously in viral (type I) interferon-treated cells: pppA(2′p5′A)n synthetase and protein kinase(s). The induction of these enzymes by T interferon was blocked by anti-T but not by antiviral interferon serum. The kinetics of the development of the antiviral state along with a comparison of the levels of pppA(2′p5′A)n synthetase and protein kinase in T and viral interferon-treated cells were investigated. In addition, [35S]methionine-labeled extracts from control, T, and viral inteferon-treated cells were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and two-dimensional gel electrophoresis. Extracts from cells treated with either type of interferon were found to contain several identical proteins, of estimated molecular weights 60,000, 88,000, and 120,000, which were absent or found at much lower levels in preparations from control cells. The newly synthesized proteins can be partially purified by chromatography on columns of poly(I)·poly(C)-Sepharose, thus providing a convenient method for their further characterization. These results show that treatment of cells with T interferon results in the induction of intracellular events identical to those observed in viral interferon-treated cells.  相似文献   
3.
HYPOTHESIS: Flat-panel based volume computed tomography could improve cochlear implant electrode evaluation in comparison with multislice computed tomography. BACKGROUND: Flat-panel based volume computed tomography offers higher spatial resolution and less metal artifacts than multislice computed tomography. Both characteristics could improve the evaluation of challenging but important questions in cochlear implantation assessment, such as an exact imaging of cochlea, osseous spiral lamina, electrode array position, and single electrode contacts. These questions are not currently fully answered by multislice computed tomography. METHODS: Four isolated temporal bone specimens were scanned in a current multislice computed tomography scanner and in two experimental flat-panel based volume computed tomography scanners before and after cochlea implantation. To compare flat-panel based volume computed tomography and multislice computed tomography, four features were rated according to the following criteria: 1) visibility of the cochlea; 2) visibility of the osseous spiral lamina; 3) discernibility of individual electrode contacts; and 4) the ability to determine the electrode array position relative to scala tympani and scala vestibuli. Layer-by-layer microgrinding pictures were used as the ground truth for verification of imaging findings. RESULTS: Flat-panel based volume computed tomography was superior to multislice computed tomography in all four features rated. The cochlea and facial nerve canal were much better delineated in flat-panel based volume computed tomography. The osseous spiral lamina and single electrode contacts were only visible in flat-panel based volume computed tomography. Assessment of implant position with regard to the cochlear spaces was considerably improved by flat-panel based volume computed tomography. CONCLUSION: Cochlear implantation assessment could be improved by flat-panel based volume computed tomography and, therefore, would be highly beneficial for cochlea implantation research and for clinical evaluation. However, these first results were shown by scanning isolated temporal bone specimens; scanning whole human skull bases might be more challenging.  相似文献   
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The aim of the present work was to evaluate the repeatability and the validity of a short food frequency questionnaire (FFQ) that could be used for older people living in Mediterranean areas. The semi-quantitative FFQ included questions regarding the frequency of consumption of the main food groups and beverages typically consumed in the Mediterranean areas as well as some questions regarding eating habits of older persons. During 2006–2007, for the repeatability assessment (within 10–30 days), 150 individuals (51 ± 17 yrs, 40% males) were studied, while another 190 individuals (74 ± 9 yrs, 52% males) were enrolled for the validation purposes. Agreement of the FFQ with the 3-day food records was evaluated using the Bland–Altman method and the Kendall's tau-b coefficient. Repeatability was tested using the Cohen's kappa coefficient. Between 3-day food records and the FFQ, good agreement for alcohol (tau-b = 0.64, p < 0.001) was found, while moderate agreement for food and beverage groups of greens (tau-b = 0.32, p < 0.001), fruits (tau-b = 0.35, p < 0.001), cereals (tau-b = 0.61, p < 0.001), sweets (tau-b = 0.51, p < 0.001), and coffee (tau-b = 0.58, p < 0.001) was observed. Low, but still significant, agreement for fish (tau-b = 0.21, p = 0.001), legumes (tau-b = 0.23, p < 0.001), vegetables (tau-b = 0.23, p < 0.001), pasta (tau-b = 0.25, p < 0.001), potatoes (tau-b = 0.17, p = 0.006) and meat consumption (tau-b = 0.14, p < 0.001) were also found. The FFQ was also valid regarding the estimation of macronutrients and energy intake. Sensitivity analyses by sex, age category (≤ or > 75 yrs), and education status showed similar validity of the FFQ in each subgroup, except for elders older than 75 years. The repeatability of the FFQ was fair in all foods tested (Cohen's kappa coefficients varied between 0.15–0.39, p-values < 0.05). The suggested FFQ seems to be a reasonably valid and repeatable measure of dietary intake and can be used in older persons living in the Mediterranean areas.  相似文献   
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Mesenteric panniculitis (MP) is a rare inflammatory and fibrotic disease of the mesentery of unknown etiology. It has various clinical and radiological manifestations, posing a diagnostic challenge for clinicians. Its diagnosis is indicated via radiologic imaging and is usually confirmed via peritoneal biopsies. We describe a case of a patient with histopathologically proven MP, in which steroid dependence was successfully managed with colchicine.  相似文献   
8.
Big Events are processes like macroeconomic transitions that have lowered social well-being in various settings in the past. Greece has been hit by the global crisis and experienced an HIV outbreak among people who inject drugs. Since the crisis began (2008), Greece has seen population displacement, inter-communal violence, cuts in governmental expenditures, and social movements. These may have affected normative regulation, networks, and behaviors. However, most pathways to risk remain unknown or unmeasured. We use what is known and unknown about the Greek HIV outbreak to suggest modifications in Big Events models and the need for additional research.  相似文献   
9.
GeroScience - The needs of the aging populations are putting increasing burden on healthcare particularly in the Western Pacific Region (WPR), which is the home of aging economies such as Hong Kong...  相似文献   
10.
ObjectivesTo estimate the effect of early application of social distancing interventions on Covid-19 cumulative mortality during the first pandemic wave.MethodsEcological longitudinal study using multivariable negative binomial regression for panel data. Daily numbers of Covid-19 cases and deaths, and data on social distancing interventions, for the 37 member countries of the Organization for Economic Cooperation and Development (OECD) were analysed.ResultsCovid-19 cumulative mortality over the first pandemic wave varied widely across countries (range, 4.16 to 855 deaths per million population). On average, one-day delay in application of mass gatherings ban was associated with an adjusted increase in Covid-19 cumulative mortality by 6.97% (95% CI, 3.45 to 10.5), whilst a one-day delay in school closures was associated with an increase of 4.37% (95% CI, 1.58 to 7.17) over the study period. We estimated that if each country had enacted both interventions one week earlier, Covid-19 cumulative mortality could have been reduced by an average of 44.1% (95% CI, 20.2 to 67.9).ConclusionsEarly application of mass gatherings ban and school closures in outbreak epicentres was associated with an important reduction in Covid-19 cumulative mortality during the first pandemic wave. These findings may support policy decision making.  相似文献   
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